Preservatives are very common in commercial and industrial products. The need for effective and economical preservative compositions is well known. There are a wide variety of applications where inhibiting the growth of microorganisms is necessary, as for example personal care products such as shampoos, conditioners, hair care products, creams, lotions, cosmetics, soap, skin care products; household products such as laundry detergents, hard surface cleaners, and fabric softeners; and industrial products and materials, such as adhesives, sizes, paper and cardboard, textiles, leather, wood, paints and articles made of plastic, and cooling lubricants. The shelf life of these preparations depends on their resistance to microbial spoilage. In addition, in many industrial applications, antimicrobial agents are useful in sealants, rope, paper pump, plastics, fuel, oil, and rubber and metal working fluids and as wood preservatives. The control of slime-producing bacteria and fungi in pump and paper mills and cooling towers is a matter of substantial commercial importance.
Examples of microorganisms which can effect contamination, degradation, or a change in the industrial environment and industrial and/or commercial materials are bacteria, fungi, yeasts, algae, and slime organisms. Microorganisms of the following genera are examples: Alternaria, such as Alternaria tenuis, Aspergillus, such as Aspergillus niger, Chaetomium, such as Chaetomium globosum, Candida, such as Candida albicans, Lentinus, such as Lentinus tigrinus, Penicillium, such as Penicillium glaucum, Trichophyton, such as Trichophyton mentagrophytes, Aureobasidium, such as Aureobasidium pullulans, Enterobacter, such as Enterobacter gergoviae, Trichoderma, such as Trichoderma viride, Escherichia, such as Escherichia coli, Pseudomonas, such as Pseudomonas aeruginosa and Pseudomonas cepacia, and Staphylococcus, such as Staphylococcus aureus and Staphylococcus epidermidas. 
Copper (II) or cupric ethanolamine aqueous solutions have an important application in the preservation of wood, and in preventing insect and fungus attack. Formulations using this biocide formulation are used through the world. Among these commercial formulations are Copper Azole (Types A and B), Ammonical and/or Amine Copper Quat (Types B, C and D), and Copper HDO. Wood preservative formulations containing copper amine plus usually at least one additional co-biocide are intended to generate wood products, resistant to decay and insect attack, which are more environmentally friendly than the previously used preservative systems.
Copper ethanolamine solutions used in the wood preservation industry are made by dissolving either single components or mixtures of copper hydroxide, copper carbonate or basic copper carbonate. For example, U.S. Pat. Nos. 5,527,384 and 5,635,217 disclose dissolution of copper carbonates in aqueous ethanolamine solutions followed by addition of the co-biocides, tebuconazole or propiconazole. However, thermal drying of these solids frequently causes copper (II) or cupric oxide to form, which is insoluble in ethanolamine and undesirable in wood preservation formulations.
U.S. Pat. No. 6,489,037 describes a coating for inhibiting stain in floor coverings that includes a copper amine complex. Copper compounds as wood preservatives are described in U.S. Pat. No. 6,352,583. Timber preservatives including a copper compound and a polyamine are described in U.S. Pat. No. 6,110,263. Liquid wood preservatives comprising a complex of a copper cation and alkoxylated diamine are described in U.S. Pat. No. 5,426,121. Wood preservatives based on a copper compound an aliphatic acid and a polyamine are described in U.S. Pat. No. 4,857,322. Water soluble copper salts are described in U.S. Pat. No. 4,808,407.
A wood preservative comprising a chromated copper arsenate, ammoniacal copper arsenate or ammoniacal copper zinc arsenate in an oil emulsion is described in U.S. Pat. No. 4,950,329 to Hickson Corporation. A method for fixing chromated copper arsenate agents in wood is described in U.S. Pat. No. 4,942,064 to Hickson Corporation. U.S. Pat. No. 5,492,681 to Hickson Corporation describes a method for producing copper oxide using a copper bearing material and ammonia. U.S. Pat. Nos. 5,427,384 and 5,634,967 and Re. 36,798 to Hickson International Plc describe a wood preservative including a cuprammonium compound and tebucanozole.
The copper salts are made from a variety of copper sources. For example, commercial processes employ scrap copper metal, spent etching solutions from the microelectronics industries or other copper-rich solids or solutions. Copper metal can be dissolved in sulfuric acid followed by addition of sodium carbonate to generate the basic copper carbonate (BCC) (H. Remy, Treatise on Inorganic Chemistry, 1956, p 389). Similarly copper metal can be dissolved in ammonia/ammonium carbonate solutions followed by boiling off the ammonia to precipitate BCC. Copper hydroxide can be produced by the addition of sodium hydroxide to an aqueous solution of a copper salt, e.g., chloride, nitrate, etc.
Electrolytic methods have been described. For example J. Errera (Bull. Acad. Belg., (5), 1, 361, 1921) described the production of basic copper carbonate at the copper anodes having pasted a current through an aqueous solution of sodium bicarbonate.
PCT WO 01/51683 A1 discloses a galvanic method of accelerating copper dissolution in nitrogen compounds. This document discloses the use of a copper anode and a cathode of silver or similar material separated by a semi-permeable membrane, and an ethanolamine solution. Passing a galvanic current through the system resulted in copper dissolution into the aqueous ethanolamine solution. It is disclosed that a copper in ethanolamine solution was obtained, but took a very long time, e.g. 45 hours. This amount of time would be commercially undesirable and higher concentrations of copper would be commercially desired, than those taught.
Copper dissolution in amine solutions has been described. There has been considerable research published on the reaction kinetics of ammonia/ammonium salt aqueous solution with copper metal in the presence of oxygen to produce aqueous solution of the copper ammoniate salt. Kinetic studies were initiated by Yamasaki (E. Yamasaki, Sci. Rep. Tohoku Imp. Univ. Ser. I, 9, 169 (1920) and later by others (R. W. Lane and H. J. McDonald, JACS, 68, 1699 (1946); J. Halpern, J. Electrochem. Soc., 100, 421 (1953); J. I. Fisher and J. Halpern, J. Electrochem. Soc., 103, 282 (1956); B. C. Y. Lu and W. F. Gordon, JACS, 77, 6136 (1955); F. Habashi, Ber. Bunsengesellschaft physik. Chem., 67 (4), 402 (1963); Z. Zembura and A. Maraszewska, Roczniki Chem., 40, 1149 (1966). ibid, Polish J. of Chem., 59, 907 (1985); R. D. Williams and S. D. Light, American Inst. Chem. Eng., 21 (1978); Z. Zembura, A. Piotrowski, and Z. Kolenda, J. Applied Electrochem., 20, 365 (1990)).
Halpern (J. Electrochem. Soc., 100, 421 (1953)) reported a study of varying ammonia and ammonium salt concentrations, oxygen partial pressures, temperatures, stirring velocities and geometric surface areas of the metallic copper. Halpern stated that at low oxygen concentrations the rate of copper dissolution was determined by the transport of oxygen to the surface. At high oxygen concentrations the rate was determined by the chemical reaction at the copper surface.
U.S. Pat. No. 6,646,147 to Richardson discloses a process for producing a copper-containing aqueous monoethanolamine solution.
Present methods of producing copper ethanolamine solutions suffer from disadvantages including long reaction times and poor yield.
There is a need for useful and efficient methods for producing copper ethanolamine aqueous solutions.